WO2021111868A1 - Coordinate system alignment method, alignment system, and alignment device for robot - Google Patents

Abstract

Provided is a system for aligning a robot coordinate system with a measuring instrument coordinate system. The system is provided with: an operation space coordinate system setting unit 31 that determines a relationship between an operation space coordinate system and the robot coordinate system through teaching of the positions of a first reference point A positioned at the origin of the operation space coordinate system, a second reference point B and a third reference point C on two lines through the first reference point; a projection line obtaining unit 432 that obtains a projection line by emitting slit light from a three-dimensional measuring instrument 4 toward a reference object 52 fixed to a plate-like member 51 arranged parallel to a plane on which two of three orthogonal axes defining the operation space coordinate system are placed, in such a way that all sides are parallel to the three orthogonal axes respectively; a measuring instrument attitude calculation unit 433 that obtains the attitude of a three-dimensional measuring instrument 30 relative to the reference object 52 on the basis of a profile of the projection line; and a measuring instrument moving unit 3 that moves the three-dimensional measuring instrument 4.

Description

Coordinate system alignment method and alignment system for robots and alignment device

The present invention relates to a technique for aligning a coordinate system as a reference for controlling the movement of a robot that executes a predetermined movement with respect to an object and a coordinate system of a three-dimensional measuring instrument attached to the robot.

Industrial robots are used on the factory production line to improve the efficiency of product assembly and processing. An industrial robot includes an arm whose tip can be moved three-dimensionally, and a jig attached to the tip to perform a predetermined treatment on an object to be processed. Further, a three-dimensional measuring instrument is attached to the tip of the arm, and for example, the object to be processed is three-dimensionally measured by an optical cutting method to specify the position and orientation thereof.

The coordinate system of the industrial robot is set in advance by the manufacturer at the time of manufacturing, etc., and the operation of the arm is controlled based on the coordinate system. On the other hand, the three-dimensional measuring instrument outputs a measurement result based on the coordinate system of the three-dimensional measuring instrument itself. Therefore, in order to move the jig to the position of the object to be processed whose position and orientation are specified by the 3D measuring instrument, the coordinate system of the robot and the coordinate system of the 3D measuring instrument are aligned (aligned). Or it is also called calibrating).

Conventionally, affine transformation by matrix calculation has been used for alignment of both coordinate systems (for example, Patent Document 1). In the alignment method described in Patent Document 1, the three-dimensional measuring instrument attached to the tip of the arm is moved to three positions that are not on the same straight line, and the same part of the object is measured at each position to three-dimensionally. Get the coordinate values in the coordinate system of the measuring instrument. Then, a matrix is created using the coordinate values in the coordinate system of the robot at the three positions and the coordinate values in the coordinate system of the three-dimensional measuring instrument acquired at each position, and the equation obtained from those matrices is solved. As a result, a transformation matrix that transforms the coordinate system of the three-dimensional measuring instrument into the coordinate system of the robot is obtained.

Japanese Unexamined Patent Publication No. 8-132373 JP-A-2019-184340 Japanese Unexamined Patent Publication No. 7-239219 Japanese Unexamined Patent Publication No. 2010-91540

In the alignment method described in Patent Document 1, in order to obtain a transformation matrix, it is necessary to expand the equations of the matrix corresponding to each of the three positions and solve a complicated equation. In addition, the development environment (development language) of the program that controls the operation of the robot differs depending on the manufacturer. Therefore, there is a problem that it is difficult to perform alignment unless an expert who understands various programming languages and can perform matrix operations.

The problem to be solved by the present invention is to provide a technique capable of easily aligning a robot coordinate system even if the person is not an expert.

The first aspect of the present invention made to solve the above problems is that the robot coordinate system, which is the coordinate system of the robot for moving the operating point three-dimensionally, and the optical cutting method can be executed. This is a method of aligning the coordinate system of a three-dimensional measuring instrument whose position and orientation with respect to the operating point are invariant.
The first reference point located at the origin in the operating space coordinate system, which is the coordinate system of the operating space of the operating point, and the second reference point and the third reference point located on two straight lines orthogonal to the first reference point, respectively. By moving the motion point to and teaching the position of each reference point, the relationship between the motion space coordinate system and the robot coordinate system is determined.
On the surface of the plate-shaped member arranged parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A rectangular parallelepiped reference object fixed to the above is irradiated with a sheet-shaped slit light from the three-dimensional measuring instrument to acquire a projection line to the reference object by the slit light.
Based on the profile of the projection line, the posture of the three-dimensional measuring instrument with respect to the reference object is obtained.
It is characterized by having a step of moving the three-dimensional measuring instrument so that the posture of the three-dimensional measuring instrument falls within a predetermined reference posture range.

The above posture means an inclination or orientation with respect to a reference such as an axis of a coordinate system or a predetermined surface. A three-dimensional measuring instrument capable of performing the optical cutting method is a three-dimensional measuring instrument that irradiates an object with slit light whose attitude with respect to the coordinate system of the measuring instrument is known, and data of projection lines on each surface of the object by the slit light. Refers to a measuring instrument capable of acquiring information on the three-dimensional shape of the object. Further, the operating space refers to a space in which the operating point of the robot operates.

In the alignment method according to the first aspect of the present invention, first, a first reference point located at the origin in the operating space coordinate system, a second reference point located on two straight lines orthogonal to the first reference point, and a second reference point, respectively. The operating point of the robot is moved to each of the third reference points, the position of each reference point is taught, and the relationship between the robot coordinate system and the operating space coordinate system is determined. That is, the first reference point and the second reference point define the first axis of the operating space coordinate system, the first reference point and the third reference point define the second axis, and further, they are orthogonal to these two axes. A third axis is defined as the axis.

Next, on the surface of the plate-shaped member parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A fixed rectangular parallelepiped reference object is irradiated with slit light from a three-dimensional measuring instrument, and projection lines on each surface of the reference object by the slit light are acquired. Then, the posture of the three-dimensional measuring instrument with respect to the reference object is obtained based on the acquired profile of the projection line. The profile of this projection line includes the length of the projection line on the upper surface of the reference object, and the projection line on the upper surface of the reference object and the projection on the surface of the plate-like member (the surface on which the reference object is placed). Includes the distance between the lines and the slope of those projection lines with respect to the coordinate axes of the 3D instrument. Then, the three-dimensional measuring instrument is moved so that the posture of the three-dimensional measuring instrument falls within a predetermined reference posture range. A specific method for obtaining the attitude of the three-dimensional measuring instrument from the profile of the projection line will be described later.

Here, for ease of understanding, the reference object is arranged on a plane including the two axes of the operating space coordinate system (this is referred to as the X axis and the Y axis) so as to be parallel to the Z axis. Further, the sheet-shaped slit light has a width in the X'axis direction of the measuring instrument coordinate system and is irradiated in the Z'axis direction, and the posture of the three-dimensional measuring instrument becomes substantially parallel to the reference object (that is,). , In this example, a specific example when the reference posture range is set so that the three axes of the robot coordinate system and the measuring instrument coordinate system are substantially parallel to each other will be described. At this time, if the three axes of the measuring instrument coordinate system are parallel to the three axes of the operating space coordinate system (and therefore parallel to the three sides of the reference object), the length of the slit light emitted to the upper surface of the reference object. The width of the reference object matches the width of the upper surface of the reference object. Further, the distance between the projection line on the upper surface of the reference object and the projection line on the surface of the plate-shaped member (the surface on which the reference object is placed) is a predetermined value based on the height of the reference object. In addition, these projection lines are parallel to the X'axis of the 3D instrument.

On the other hand, the greater the rotation of the measuring instrument coordinate system around the Z axis of the operating space coordinate system, the longer the length of the slit light radiated to the upper surface of the reference object. Further, when the measuring instrument coordinate system is tilted with respect to the operating space coordinate system around one axis (this is defined as the Y axis) in the plane, the projection line on the upper surface of the reference object and the surface of the plate-shaped member (reference). The inclination of the projection line to the plane on which the object is fixed) with respect to the X'axis of the 3D measuring instrument becomes large. In addition, a cutting line irradiated with slit light may appear on the side surface of the reference object. Furthermore, the greater the tilt of the measuring instrument coordinate system with respect to the operating space coordinate system around another horizontal axis (this is the X axis), the more the projection line on the upper surface of the reference object and the surface of the plate-like member. The distance between the projection lines to is increased. Therefore, from this information, the posture of the three-dimensional measuring instrument with respect to the reference object (in this example, the inclination of the axis of the measuring instrument coordinate system with respect to each of the three axes of the operating space coordinate system) can be obtained.

Then, when any of the inclinations is larger than the predetermined threshold value, the three-dimensional measuring instrument is moved so that all the inclinations are lower than the threshold value. For example, the user operates the controller while visually recognizing the posture of the three-dimensional measuring instrument with respect to the reference object to move the three-dimensional measuring instrument so as to be parallel to the reference object, and the inclination is set at that position. This can be done by confirming that all of them are below the above threshold. As a result, the posture of the three-dimensional measuring instrument can be set within the reference posture range (in this example, the direction in which the three sides of the reference object extend and the three axes of the measuring instrument coordinate system are parallel).

As described above, since the alignment method according to the first aspect of the present invention does not need to perform matrix operations using a programming language, it is possible to easily align the robot coordinate system even if the person is not an expert.

The above alignment method is, for example, a three-dimensional measuring instrument so as to have a predetermined reference posture with respect to a rectangular parallelepiped reference object arranged so that each side is parallel to each of the three orthogonal axes of one operating space coordinate system. The posture of the object is determined, and the object is three-dimensionally measured at the position and the posture. That is, in the above alignment method, one position and orientation of the three-dimensional measuring instrument are determined with respect to one operating space coordinate system, and the three-dimensional measurement data of the object is acquired at the position and orientation. In many cases, the object to be assembled or processed on the production line of a factory has a three-dimensional shape, and there is a shadowy part just by acquiring the three-dimensional measurement data of the object at one position and posture. It exists and it is not possible to obtain information on the shape of the object for that part. Therefore, it is required to acquire information on the shape of the object from a plurality of directions.

Therefore, in the alignment method according to the second aspect of the present invention, in the above first aspect,
As the operating space coordinate system, a reference operating space coordinate system and a reference operating space coordinate system are set.
The operating point is moved between the origin of the reference operating space coordinate system and the origin of the reference operating space coordinate system to obtain translational displacement and rotational displacement.
Based on the translational displacement and the rotational displacement, a transformation matrix for converting the reference operating space coordinate system into the reference operating space coordinate system is obtained.
In each of the reference motion space coordinate system and the reference motion space coordinate system, the three-dimensional measuring instrument is moved so that the posture of the three-dimensional measuring instrument falls within the predetermined reference posture range, and the object is three-dimensional. Get measurement data,
The object acquired in the reference space coordinate system by converting the three-dimensional measurement data of the object acquired in the reference operation space coordinate system into the three-dimensional measurement data of the reference operation space coordinate system using the conversion matrix. It is preferable to configure it so as to integrate it with the three-dimensional measurement data of the object.

In the alignment method of the second aspect described above, the reference operating space coordinate system and the reference operating space coordinate system are set. Then, the motion point of the robot is moved between the origins of both coordinate systems, the translational displacement and the rotational displacement due to the movement are acquired, and the reference motion space coordinate system is converted into the reference motion space coordinate system based on the displacement. Find the matrix. After that, the three-dimensional measurement data of the object is acquired by the three-dimensional measuring instrument in each of the reference motion space coordinate system and the reference motion space coordinate system, and the three-dimensional measurement acquired in the reference motion space coordinate system using the above conversion matrix. The data is converted into 3D measurement data of the reference operating space coordinate system and integrated. In the alignment method of this aspect, the object can be three-dimensionally measured at a plurality of positions and postures, and information on the shape of the object without a shaded portion can be obtained.

The movable range of the operating point of the robot is determined by the length of the arm, and if the object is large with respect to the robot, the arm cannot reach the opposite side of the object with only one robot, and a part of the object cannot be reached. It may not be possible to acquire 3D measurement data.

Therefore, in the alignment method according to the third aspect of the present invention, in the second aspect described above,
For each of the plurality of robots, a plurality of operating space coordinate systems are set, which are the plurality of the operating space coordinate systems, one of which is common to the operating space coordinate system set for at least one other robot. ,
One of all the motion space coordinate systems set in the plurality of robots is the reference motion space coordinate system, and the other is the reference motion space coordinate system.
Among the coordinate systems set in the plurality of robots, a transformation matrix for converting the reference motion space coordinate system to the reference motion space coordinate system is created.
Three-dimensional measurement data of the object is acquired in each of the plurality of operating space coordinate systems set for each of the plurality of robots.
The three-dimensional measurement data of the object acquired in the reference motion space coordinate system may be converted into the three-dimensional measurement data of the reference motion space coordinate system and integrated.

In the alignment method of the third aspect, since the three-dimensional measurement data of the object is acquired by using a plurality of robots, the three-dimensional shape information has no shadow even when the object is larger than the robot. Can be obtained.

A fourth aspect of the present invention made to solve the above problems is that the robot coordinate system, which is the coordinate system of the robot for moving the operating point three-dimensionally, and the optical cutting method can be executed. A system that aligns the coordinate system of a three-dimensional measuring instrument whose position and orientation with respect to the operating point are invariant.
The first reference point located at the origin in the operating space coordinate system, which is the coordinate system of the operating space of the operating point, the second reference point and the third reference point located on two straight lines orthogonal to the first reference point, respectively. An operating space coordinate system setting unit that determines the relationship between the operating space coordinate system and the robot coordinate system by moving the operating point to a point and teaching the position of each reference point.
On the surface of the plate-shaped member arranged parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A projection line acquisition unit that irradiates a rectangular parallelepiped reference object fixed to the above with a sheet-shaped slit light from the three-dimensional measuring instrument and acquires a projection line to the reference object by the slit light.
A measuring instrument posture calculation unit that obtains the posture of the three-dimensional measuring instrument with respect to the reference object based on the profile of the projection line.
It is characterized by including a measuring instrument moving unit for moving the three-dimensional measuring instrument.

The alignment system according to the fifth aspect of the present invention has the fourth aspect described above.
The operating space coordinate system setting unit sets the reference operating space coordinate system and the reference operating space coordinate system as the operating space coordinate system.
further,
A displacement acquisition unit that moves the operating point between the origin of the reference operating space coordinate system and the origin of the reference operating space coordinate system to acquire translational displacement and rotational displacement.
A transformation matrix calculation unit that obtains a transformation matrix that converts the reference motion space coordinate system into the reference motion space coordinate system based on the translational displacement and the rotational displacement.
In each of the reference motion space coordinate system and the reference motion space coordinate system, the three-dimensional measuring instrument is moved by the measuring instrument moving unit so that the posture of the three-dimensional measuring instrument falls within the predetermined reference posture range. , The 3D measurement data acquisition unit that acquires the 3D measurement data of the object,
The object acquired in the reference space coordinate system by converting the three-dimensional measurement data of the object acquired in the reference operation space coordinate system into the three-dimensional measurement data of the reference operation space coordinate system using the conversion matrix. It may be equipped with a three-dimensional measurement data integration unit that integrates with the three-dimensional measurement data of an object.

Further, the alignment system according to the sixth aspect of the present invention further comprises the fifth aspect.
Equipped with multiple robots
The operating space coordinate system setting unit is common to a plurality of the operating space coordinate systems set for each of the plurality of robots, one of which is set for at least another robot. A plurality of operating space coordinate systems are set, and one of the operating space coordinate systems set for the plurality of robots is set as the reference operating space coordinate system, and the other is set as the reference operating space coordinate system.
The transformation matrix calculation unit creates a transformation matrix that converts the reference motion space coordinate system into the reference motion space coordinate system among the coordinate systems set in the plurality of robots.
The three-dimensional measurement data integration unit acquires three-dimensional measurement data of the object in each of the plurality of operating space coordinate systems set for each of the plurality of robots.
The three-dimensional measurement data integration unit may convert the three-dimensional measurement data of the object acquired in the reference motion space coordinate system into the three-dimensional measurement data of the reference motion space coordinate system and integrate the data. it can.

A seventh aspect of the present invention made to solve the above problems is the operation of the operating point associated with the robot coordinate system, which is the coordinate system of the robot for moving the operating point three-dimensionally. Used to align the operating space coordinate system, which is the coordinate system of space, with the coordinate system of the measuring instrument, which is the coordinate system of the three-dimensional measuring instrument that can execute the optical cutting method and whose position and orientation with respect to the operating point are invariant. It is a device that can be used
On the surface of the plate-shaped member arranged parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A projection line acquisition unit that irradiates a rectangular parallelepiped reference object fixed to the reference object with a sheet-shaped slit light from the three-dimensional measuring instrument and acquires a projection line to the reference object by the slit light.
A measuring instrument posture calculation unit that obtains the posture of the three-dimensional measuring instrument with respect to the reference object based on the profile of the projection line.
It is characterized by having.

By using the coordinate system alignment method for the robot, the alignment system, or the alignment device according to the present invention, the robot coordinate system can be easily aligned even by a non-expert.

FIG. 6 is a schematic configuration diagram of a robot system including a coordinate system alignment device for a robot and a first embodiment of the alignment system according to the present invention. The figure explaining the structure of the 3D sensor of 1st Example. The figure explaining the arrangement of the slit light irradiation part of the 3D sensor and the area sensor. The flowchart regarding 1st Example of the coordinate system alignment method for a robot which concerns on this invention. The figure explaining the alignment jig used in 1st Example. The figure explaining the projection line to the block by the slit light in 1st Example. An example of the projection line profile obtained in the first embodiment. FIG. 6 is a schematic configuration diagram of a robot system including a second embodiment of a coordinate system alignment device and an alignment system for a robot according to the present invention. The figure explaining the structure of the control / processing part in the robot system of 2nd Example. The flowchart regarding the 2nd Example of the coordinate system alignment method for a robot which concerns on this invention. The figure explaining the relationship of the operation space coordinate system in 2nd Example. The result of integrating the three-dimensional measurement data of the object using the robot system of the second embodiment. FIG. 6 is a schematic configuration diagram of a robot system including a third embodiment of a coordinate system alignment device and an alignment system for a robot according to the present invention. The flowchart regarding the 3rd Example of the coordinate system alignment method for a robot which concerns on this invention. The figure explaining the relationship of the operation space coordinate system in 3rd Example. The figure explaining the relationship between the arrangement of the robot and the operating space coordinate system in the modification of the 3rd Example.

<First Example>
A coordinate system alignment method for a robot, an alignment system, and a first embodiment of an alignment device according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a main part of a robot system 1 including a coordinate system alignment system and device for a robot according to the first embodiment (hereinafter, referred to as “alignment system” and “alignment device”).

The robot system 1 of the first embodiment includes a robot 2 and a controller 3 for operating the robot 2.

The robot 2 includes an arm portion 21 provided with an operating point 20 at the tip thereof, a linear motion mechanism 22a to 22c for three-dimensionally moving the arm portion 21, and a rotation mechanism 23a to 23c. The linear motion mechanisms 22a to 22c and the rotation mechanisms 23a to 23c operate under the control of the controller 3. The controller 3 has an operating space coordinate system setting unit 31 as a functional block for determining the relationship between the operating space coordinate system and the robot coordinate system by teaching described later.

A three-dimensional sensor 4 is detachably attached in the vicinity of the operating point 20 of the arm portion 21. As shown in FIG. 2, the three-dimensional sensor 4 includes a slit light irradiation unit 41 that irradiates an object with slit light, and an area sensor 42 that captures a projection line of the slit light onto the object. The measuring instrument coordinate system is defined in these, and as shown in FIG. 3, the light irradiation unit 41 is arranged in a state of being tilted by an _{angle θ 1 with respect to the X'-Z'plane of the measuring instrument coordinate system, and is an area.} The sensor 42 is arranged on the side opposite to the slit light irradiation unit 41 with the X'-Z'plane in between, at an angle of θ _{2 with respect to the same plane. Although θ 1} in the first embodiment is 0, this is not an essential requirement for the present invention, and as long as _{the angle of θ 1} is known, how the projection line to the object can be applied to the area sensor 42. You can figure out if you can catch it. Therefore, the processing described below can be performed by an appropriate arithmetic processing based on the known angle.

In the first embodiment, the slit light irradiation unit 41 is arranged on an X'-Z'plane, and slit light is emitted along the X'-Z'plane (slit light having a width in the X'axis direction is emitted in the Z'axis direction. Irradiate the object (towards). θ ₂ is set to an appropriate angle in the range of, for example, 30 ° to 40 °. In the first embodiment, as the three-dimensional sensor 4, aberrations and depth aberrations (aberrations caused by the perspective method within the angle of view when the camera is oriented in an oblique direction) caused by the lens included in the optical system of the sensor 4 are detected. Use the one to correct. As a result, accurate measurement is performed in the optical cutting method described later, and the alignment accuracy of the coordinate system is improved.

The three-dimensional sensor 4 is further provided with a control / processing unit 43. In addition to the storage unit 431, the control / processing unit 43 includes a projection line acquisition unit 432, a measuring instrument posture calculation unit 433, and a coordinate system shift unit 434 as functional blocks. The control / processing unit 43 of the first embodiment is configured as an arithmetic processing mechanism incorporated inside the three-dimensional sensor 4. Further, the control / processing unit 43 is connected to an input unit 45 for the user to give an appropriate input instruction and a display unit 46 for displaying the measurement result or the like via a predetermined communication interface 44. There is. The control / processing unit 43 may also be configured by a portable terminal or the like provided separately from the three-dimensional sensor 4 and capable of communicating with the three-dimensional sensor 4.

Next, the procedure of the alignment method of the first embodiment will be described with reference to the flowchart of FIG.

First, prepare a jig for alignment. The alignment jig 5 includes a plate-shaped member 51 and a block 52 fixed on the plate-shaped member 51. As shown in FIG. 5, the upper surface of the plate-shaped member 51 is a plane including two axes (X-axis and Y-axis) of the operating space coordinate system, which is the coordinate system of the space in which the operating point 20 of the robot 2 is operated. It is fixed in the matching position. Further, a reference point A is set at a position on the upper surface of the plate-shaped member 51 corresponding to the origin of the operating space coordinate system, a reference point B is set at a predetermined position on the X axis of the operating space coordinate system, and Y of the operating space coordinate system is set. A reference point C is set at a predetermined position on the axis. That is, the reference points A and B define the X-axis direction of the operating space coordinate system, and the reference points A and C define the Y-axis of the operating space coordinate system.

The size of the block 52 is W (mm) in the X-axis direction, L (mm) in the Y-axis direction, and H (mm) in the Z-axis direction. The length of the block 52 in the X-axis direction is preferably as long as possible within the field of view of the area sensor 42. As a result, the projection line of the slit light reflected on the upper surface of the block 52 becomes longer when the process described later is performed, and the accuracy when determining the posture of the three-dimensional sensor 4 with respect to the block 52 becomes higher.

On the other hand, the length of the block 52 in the Y-axis direction is, for example, 10 to 100 mm, and may be appropriately determined in consideration of the size of the robot and the like. By lengthening the Y-axis direction of the block 52, is the projection line of the slit light parallel to one side of the block 52 (the side parallel to the X-axis of the operating space coordinate system) when the block 52 is irradiated with the slit light? It becomes easier to visually recognize whether or not. If the Y-axis direction of the block 52 is made too short, the projection line of the slit light crosses one side of the block 52 (the side parallel to the X axis of the operating space coordinate system), and the projection line crossing the upper surface of the block 52 is formed. It becomes difficult to obtain.

In the conventional coordinate system alignment method, a jig with a sharp tip as much as possible may be used in order to accurately position the operating point, but if a jig with a sharp tip is used, diffuse reflection of light occurs. It was easy, and it was sometimes difficult to take an image when confirming the positional relationship between the operating point and the tip of the jig. On the other hand, in the first embodiment, since the coordinate system is aligned by the method and device described later, it is not necessary to use a jig with a sharp tip, and a rectangular parallelepiped block 52 may be used, so diffuse reflection does not occur. , The projection line and the like, which will be described later, are easily and accurately imaged.

In addition, the surface of the block 52 is subjected to a matte treatment to suppress diffused reflection of light. For the block 52, for example, one made of matte alumite can be preferably used. The block 52 is arranged parallel to the three axes of the operating space coordinate system so that the center of the bottom surface of the block 52 is located at a predetermined coordinate in the operating space coordinate system. In this way, the alignment jig is installed (step 1. see FIG. 5).

Subsequently, the controller 3 moves the arm portion 21, moves the operating point 20 to the reference point A, and teaches the robot 2 the position of the reference point A. Similarly, the operating points 20 are also moved to the reference points B and C, and their positions are taught to the robot 2 (step 2). At this time, the user may operate the controller 3 by himself / herself, or the operating point 20 may be moved to each reference point by the operating space coordinate system setting unit 31. After that, the operation space coordinate system setting unit 31 registers the coordinates of the reference points A, B, and C in the operation space coordinate system in the robot 2, and the robot coordinates registered in advance (for example, at the time of shipment) in the robot 2. Determine the relationship between the system and the operating space coordinate system. In this way, the operating space coordinate system is set in the robot 2 (step 3).

After setting the operating space coordinate system in the robot 2, the arm portion 21 is moved by the controller 3 and the three-dimensional sensor 4 is positioned above the block 52 as shown in FIG. 5 (step 4). In FIG. 5, the robot 2 other than the arm portion 21 is not shown. Subsequently, the slit light irradiation unit 41 irradiates the block 52 with slit light (step 5), and the area sensor 42 acquires a projection line to the block 52 (step 6).

The slit light in the first embodiment is light having a width in one axis (X'axis) direction of the measuring instrument coordinate system that is a reference of the output signal of the three-dimensional sensor 4, and is another one axis (X'axis) of the measuring instrument coordinate system. It is emitted in the Z'axis) direction. That is, it is a sheet-shaped slit light along the X'-Z'plane of the measuring instrument coordinate system (see FIG. 6). The three-dimensional sensor 4 of the first embodiment corrects aberrations and depth aberrations (aberrations caused by the perspective method within the angle of view when the camera is oriented in an oblique direction) caused by a lens included in the optical system of the sensor 4. To do. Specifically, it is specified at which position of the two-dimensionally arranged pixels the slit light is incident, and then the position is corrected by calibration. Then, the profile of the projection line is acquired from the position of the corrected pixel.

As described above, the three sides of the block 52 are arranged parallel to the three axes of the operating space coordinate system, and the slit light is a sheet-like light along the X'-Z'plane. Therefore, if the X-axis, Y-axis, and Z-axis of the operating space coordinate system and the X'-axis, Y'-axis, and Z-axis of the measuring instrument coordinate system are parallel to each other, the upper surface of the block 52 can be reached. The projection line is the same as the length W of one side parallel to the X axis of the block 52. Further, the distance between the projection line on the upper surface of the block 52 and the projection line on the plate-shaped member 51 is the height H of the block 52 (and the area sensor 42 of the three-dimensional sensor 4 sets the block and the plate-shaped member 51. It depends on the angle of capture).

On the other hand, when the measuring instrument coordinate system is tilted with respect to the operating space coordinate system, a projection line having a different length and distance from the above appears. The projection lines that appear in such a case will be described with reference to FIGS. 6 and 7. FIG. 6 shows a state in which slit light is irradiated from an oblique direction with reference to the jig 5 (plate-shaped member 51 and block 52). In FIG. 6, in order to make the angles α, β, and γ easy to understand, the projection lines are shown by making these angles larger than they actually are. FIG. 7 is a display example created based on the projection line measured by the area sensor 42.

In the case of the first embodiment, the area sensor 42 is _{arranged at a position tilted by an angle θ 2 with} respect to the X'-Z'plane, and the projection line is photographed from diagonally above. Therefore, the distance between the projection line on the upper surface of the block 52 and the projection line on the plate-shaped member 51 captured by the area sensor 42 is shorter than the actual distance. Therefore, the projection line acquisition unit 432 corrects the distance based on the arrangement of the slit light irradiation unit 41 and the area sensor 42 (angles θ ₁ and θ _{2 with} respect to the X'-Z'plane) and the actually measured distance. And find the measured value h. On the other hand, the length of the projection line on the upper surface of the block 52 is taken as the measured value w as it is. Then, as shown in FIG. 7, the measured values w and h are displayed on the display unit 46.

Here, as shown in FIGS. 6 and 7, the measuring instrument coordinate system passes through one end of the projection line on the upper surface of the block 52 (the bending point of the projection line when the projection line on the side surface of the block 52 is also photographed). The angle formed by the straight line parallel to the Z'axis and the straight line passing through one end and parallel to the Z axis of the operating space coordinate system is α, and one direction (horizontal direction) of the angle of view of the area sensor 42 and the area sensor 42. The angle formed by the projection line captured in 1 is defined as β, and the angle formed by the projection line on the upper surface of the block 52 and the straight line passing through one end of the projection line and parallel to the X axis of the operating space coordinate system is defined as γ.

If the angles α, β, and γ are defined as described above, the angles α and α and the lengths H in the X-axis direction and the length H in the Z-axis direction of the block 52 and the measured values w and h are calculated by the following equations. γ is required.
α = cos ^-1 (H / h)… (1)
γ = cos ^-1 (W / w)… (2)
Further, the angle β is obtained as an angle formed by the lateral direction of the area sensor 42 angle of view and the projection line on the plate-shaped member 51 as described above.

The measuring instrument posture calculation unit 433 calculates the above angles α, β, and γ from the projection line profile as described above (step 7), and displays each angle on the screen of the display unit 46.

After calculating the angles α, β, and γ, the measuring instrument posture calculation unit 433 determines whether all of these values are equal to or less than a predetermined value (predetermined value) (step 8). This predetermined value is set to a value at which each axis of the operating space coordinate system and each axis of the measuring instrument coordinate system can be regarded as substantially parallel to each other. The predetermined value is, for example, 0.2 degrees. If the angles α, β, and γ are all equal to or less than the predetermined values (YES in step 8), the process proceeds to step 10 described later.

On the other hand, if any of the angles exceeds a predetermined value (NO in step 8), the user adjusts the posture of the three-dimensional sensor 4 using the controller 3 (step 9). Then, returning to step 5, the block 52 is irradiated with slit light again, the angles α, β, and γ are calculated and displayed on the display unit 46, and it is determined whether all of them are equal to or less than a predetermined value ( Steps 5-8). These processes are repeated until the angles α, β, and γ are all equal to or less than a predetermined value. In the first embodiment, each time the angles α, β, and γ are calculated, those values are displayed on the display unit 46. Therefore, the user confirms the angles α, β, and γ, and operates with the coordinates of the measuring instrument. It is possible to intuitively grasp how much the spatial coordinates are deviated. It is also possible to determine to what extent it is necessary to match both coordinates while checking the change in the value and considering the accuracy required for the work to be performed using the robot 2. ..

When the above angles α, β, and γ are all equal to or less than a predetermined value (YES in step 8), the coordinate system shift unit 434 directs the slit light from the three-dimensional sensor to the Y'axis (operating space coordinate system and measuring instrument coordinate system). Scan in the direction (substantially the same as the Y axis because they are parallel to each other) to acquire the three-dimensional measurement data of the entire block 52, and position the block 52 at a predetermined position (for example, on the XY plane of the operating space coordinate system). The coordinate position of the bottom surface of the block 52) in the measuring instrument coordinate system is obtained (step 10). Then, the difference (shift amount) is obtained by comparing with the predetermined position coordinate position of the block 52 in the operating space coordinate system (step 11). Finally, the measuring instrument coordinate system and the operating space coordinate system are matched by shifting the measuring instrument coordinate system by the magnitude of the shift amount.

<Second Example>
Next, the second embodiment will be described. As shown in FIG. 8, the robot system 100 of the second embodiment includes a control / processing device 6 in addition to the configuration of the alignment system 1 of the first embodiment. The control / processing device 6 is provided so as to be able to communicate with the robot 2, the three-dimensional sensor 4, and the controller 3.

As shown in FIG. 9, in addition to the storage unit 61, the control / processing device 6 has a displacement acquisition unit 621, a transformation matrix creation unit 622, a three-dimensional measurement data acquisition unit 623, and three-dimensional measurement data integration as functional blocks. The unit 624 is provided. The substance of the control / processing device 6 is, for example, a general personal computer, and each of the above functional blocks is embodied by executing the pre-installed three-dimensional measurement data processing program 62. Here, the control / processing unit 43 and the control / processing device 6 of the three-dimensional sensor 4 are provided respectively, but a part or all of the functions of the control / processing unit 43 of the three-dimensional sensor 4 are controlled / processed. The configuration incorporated in 6 can also be adopted.

The operation of each part and the flow of data processing in the second embodiment will be described with reference to the flowchart of FIG. The operation and processing common to the first embodiment will be omitted as appropriate.

In the first embodiment, one position and orientation of the three-dimensional sensor 4 are determined for one operating space coordinate system, and measurement data is acquired in three dimensions of the object at the position and orientation. Therefore, when the object has a three-dimensional shape, the portion on the opposite side of the three-dimensional sensor 4 across the object is shaded, and that portion cannot be measured three-dimensionally.

Therefore, in the second embodiment, the user first sets a plurality of operating space coordinate systems corresponding to the postures of the robot 2 by the same procedure as in the first embodiment. These plurality of operating space coordinate systems are set so that the part that is shaded in the three-dimensional measurement in the first embodiment can also be three-dimensionally measured. Then, one of these plurality of operating space coordinate systems is used as the reference operating space coordinate system, and the other operating space coordinate systems are used as the reference operating space coordinate system (step 21). Hereinafter, a case where two reference operating space coordinate systems (first reference operating space coordinate system and second reference operating space coordinate system) are set will be described as an example. Hereinafter, the reference operating space coordinate system is referred to as Σ _A , the first reference operating space coordinate system is referred to as Σ _B , and the second reference operating space coordinate system is referred to _{as Σ C.} The number of reference operating space coordinate systems may be one or three or more.

Next, for each of the reference operating space coordinate system Σ _A , the first reference operating space coordinate system Σ _B , and the second reference operating space coordinate system Σ _C , the three-dimensional sensor 4 is subjected to the same procedure as in the first embodiment. The position and posture are determined (step 22).

The relationship between the ^{position vector B} r represented by the _{coordinate system Σ B} ^{and the position vector A} r represented by the coordinate system Σ _A with respect to the points existing in the three-dimensional space that sets the reference motion space coordinate system and the reference motion space coordinate system is It is expressed by the following equation.

Here, ^A T _B is a homogeneous transformation matrix, and can be represented by the following matrix including ^{the rotation transformation B} R _A and the translation ^B P _{A as elements.}

To find the matrix elements of this homogeneous transformation matrix, find the position and orientation of the origin of the coordinate system Σ _{B in the coordinate system Σ A.}

Specifically, the displacement acquisition unit 621 sets the operating point 20 of the robot 2 to the origin (x _A = 0, y _A = 0, z _A = 0, r _xA = 0, r) _{of the reference operating space coordinate system Σ A. Set yA} = 0, r _zA = 0), and then refer to the operating point 20. Origin of the _{operating space coordinate system Σ B (x B} = 0, y _B = 0, z _B = 0, r _xB = 0, r _yB = 0, is moved to r _zB = 0) (step 23). Then, the translational displacement and the rotational displacement in the reference operating space coordinate system Σ _A when the operating point 20 is at the origin of the reference operating space coordinate system Σ _{B are acquired.} This can be read from the controller 3 that controls the operation of the robot 2. The transformation matrix creation unit 622 creates a homogeneous transformation matrix ^A T _B based on these translational displacements and rotational displacements (step 24). This homogeneous transformation matrix ^A T _B transforms the coordinates in the reference operating space coordinate system Σ _{B into} the coordinates in the reference operating space coordinate system Σ _A.

By performing the same process described above for the second reference operating space coordinate system sigma _C, homogeneous transformation matrix ^A T _C is obtained for converting the second reference operating space coordinate system sigma _C in standard operating space coordinate system sigma _A ..

Next, the three-dimensional measurement data acquisition unit 623 performs three-dimensional measurement of the object in each of the _{reference operating space coordinate system Σ A} , the first reference operating space coordinate system Σ _B , and the second reference operating space coordinate system Σ _C. Acquire the data (step 25). Then, the three-dimensional measurement data integration unit 624 inputs the three-dimensional measurement data _{of the object in the first reference operating space coordinate system Σ B} and the second reference operating space coordinate system Σ _C , respectively, into the same-order conversion matrices ^A T _B and ^A. It is converted into three-dimensional measurement data of the reference operating space coordinate system Σ _{A by T C (step 26, FIG. 11).} The three-dimensional measurement data integration unit 624 integrates the three-dimensional measurement data _{of the object in the reference operating space coordinate system Σ A} thus obtained and the three-dimensional measurement data of the object acquired in the _{reference operating space coordinate system Σ A (} Step 27), the display is displayed on the screen of the display unit 66 (step 28). The user can confirm the shape of the object from an arbitrary direction by rotating the three-dimensional measurement data of the object displayed on the screen of the display unit 66 by an appropriate operation through the input unit 65. it can.

FIG. 12 shows the result of integrating the three-dimensional measurement data of the object acquired by the three-dimensional sensor 4 at the positions and orientations corresponding to the three different operating space coordinate systems. FIG. 12 (a) is an optical image of the object, and FIG. 12 (b) is the result of integrating the three-dimensional measurement data of the object acquired in three different coordinate systems. In the second embodiment, the motion point 20 of the robot 2 is moved between the origin of the reference motion space coordinate system and the origin of the reference motion space coordinate system to acquire translational displacement and rotational displacement, and the reference motion is based on the displacement. By simply finding the conversion matrix that converts the spatial coordinate system to the reference operating space coordinate system, it is possible to easily integrate the three three-dimensional measurement data acquired by the three-dimensional sensor 4 according to the positions and orientations corresponding to the different operating space coordinate systems. Can be done.

As a technique for processing three-dimensional measurement data, for example, the technique described in Patent Document 2-4 has been conventionally proposed. However, in these methods, the resolution of the three-dimensional measurement data may decrease due to, for example, shear deformation or scaling. In addition, in these techniques, it is necessary to perform complicated calculations to obtain the elements of the homogeneous transformation matrix at the time of data integration. For example, the coordinate values of a plurality of positions are obtained separately from the operating space coordinate system of the robot. It is necessary to obtain the homogeneous transformation matrix from them. However, it is difficult for an operator to perform such advanced arithmetic processing at a work site such as a factory where many robot systems are used.

On the other hand, in the second embodiment, the operating space coordinate system is set by using the alignment jig 5 as in the first embodiment. Therefore, unlike Patent Document 2-4, shear deformation and scaling do not occur, and three-dimensional measurement data can be easily integrated while maintaining high resolution and accuracy.

<Third Example>
A third embodiment will be described. As shown in FIG. 13, the robot system 200 of the third embodiment includes a plurality of robots 2a and 2b, controllers 3a and 3b that control the operations of the robots 2a and 2b, and a control / processing device 7. The robots 2a and 2b and the controllers 3a and 3b have the same configurations as the robots 2 and the controller 3 in the first and second embodiments. Further, the control / processing device 7 has the same configuration and functional blocks as the control / processing device 6 in the second embodiment. Here, the configuration is provided with two robots for the sake of simplicity, but a system including three or more robots 2 may be used.

The movable range of the operating point 20 of the robot 2 in the second embodiment is determined by the lengths of the linear motion mechanisms 22a to 22c for moving the arm portion 21, and if the object is larger than the robot 2, only one robot 2 is used. Then, the arm may not reach the opposite side of the object, and it may not be possible to acquire three-dimensional measurement data of a part of the object. Further, in a system using only one robot 2, it is not possible to obtain three-dimensional measurement data of an object from a plurality of directions at the same time.

Therefore, in the third embodiment, three-dimensional measurement data of the object is acquired by using a plurality of robots 2. The operation of each part and the flow of data processing in the third embodiment will be described with reference to the flowchart of FIG. Descriptions of operations and processes common to those of the first embodiment or the second embodiment will be omitted as appropriate.

First, for the robot 2a, the connected motion space coordinate system Σ _A and the reference motion space coordinate system Σ _B are set. Also, for the robot 2b, the connected motion space coordinate system Σ _A and the reference motion space coordinate system Σ _C are set. That is, a connected motion space coordinate system common to the plurality of robots 2 is set, and a unique reference motion space coordinate system is set for each robot 2 (step 31; see FIG. 15). The connected operating space coordinate system Σ _A corresponds to the reference operating space coordinate system in the third and sixth aspects of the present invention. For either robot, the connected operating space coordinate system Σ _A and the reference operating space coordinate system Σ _B may be the same coordinate system.

Next, the position and orientation of the three-dimensional sensor 4 in each operating space coordinate system are determined by the same procedure as in the first embodiment (step 32).

Further, the homogeneous transformation matrix for converting the reference motion space coordinate systems Σ _B and Σ _C set in the robots 2a and 2b into the connected motion space coordinate system Σ _{A is obtained by the same procedure as in the second embodiment (step 33).} ).

After that, the three-dimensional measurement data of the object is acquired in the reference motion space coordinate systems Σ _B and Σ _{C in each of the robots 2a and 2b (step 34).} Then, the three-dimensional measurement data of the object in the reference motion space coordinate system Σ _B and Σ _C are converted into the three-dimensional measurement data of the connected motion space coordinate system Σ _A ^{by the same-order transformation matrices A} T _B and ^A T _C , respectively. (Step 35. FIG. 15). Thus, different robot 2a, the three-dimensional measurement data of the acquired object in a three-dimensional sensor 4 attached to 2b, can be integrated with three-dimensional measurement data of the object in the reference operation space coordinate system sigma _A (Step 36 ). The integrated data is displayed on the screen of the display unit 66 (step 37).

In the third embodiment, since a plurality of robots 2a and 2b are used, it is possible to acquire the three-dimensional measurement data of the entire large object without being restricted by the length of the arm of the robot 2. In addition, three-dimensional measurement data of the object can be obtained from a plurality of directions at the same time.

In the above explanation, the common connection operation space coordinate system Σ _A is set for the two robots 2, but when the object to be transported is measured by the three-dimensional sensors 4 attached to many robots 2, all the robots. It may be difficult to set the connection operation space coordinate system common to 2. In such a case, for each of the plurality of robots 2, there are a plurality of motion space coordinate systems, one of which is common to the motion space coordinate system set for at least another robot. The coordinate system may be set.

FIG. 16 shows a robot system 300 of a modified example of the third embodiment. In this robot system 300, the object 9 conveyed by the belt conveyor 8 is monitored. A plurality of robots 2a, 2b ... Are arranged along the transport direction of the object 9 on one side of the belt conveyor 8, and a plurality of robots 2e, 2f ... Are arranged on the other side.

Only the reference operating space coordinate system Σ _A is set for the robot 2a. Further, the connected operation space coordinate system Σ _A and the reference operation space coordinate system Σ _B are set in the robot 2b. For the robot 2c and below, the connected motion space coordinate system and the reference motion space coordinate system common to the adjacent robots 2 are set. _{Further, the connected operating space coordinate system Σ A} and the reference operating space coordinate system Σ _E are set in the robot 2e located on the opposite side of the robot 2a with the belt conveyor 8 in between. For the robot 2f and below, the connected motion space coordinate system and the reference motion space coordinate system common to the adjacent robots 2 are set.

As described in the third embodiment, these coordinate systems can be transformed with each other using the corresponding linear transformation matrices. For example, as shown in FIG. 16, the three-dimensional measurement data acquired in _{the reference motion space coordinate system Σ F} ^{of the robot 2f is converted in order by two homogeneous transformation matrices E} T _F and ^A T _E to obtain the reference motion space coordinates. It can be converted into 3D measurement data of system Σ _A. As described above, in the modified example system 300, the three-dimensional measurement data of the object 9 acquired in all the reference motion space coordinate systems is used in the reference motion space coordinate system Σ _A by using one or more homogeneous transformation matrices. Convert to 3D measurement data and combine them. This makes it possible to monitor an object 9 that moves due to transportation or the like in a wide range.

The specific configurations and numerical values described in the above examples are all examples, and can be appropriately changed according to the gist of the present invention.

In the above embodiment, the jig 5 was used to determine the shift amount of both coordinate systems, and even the process of shifting and matching the same coordinate system was performed, but these processes are not essential. For example, when actually operating the robot, the process of adding (or subtracting) the above shift amount to the position acquired in the measuring instrument coordinate system to convert it to the position in the operating space coordinate system is actually operated. You may go every time. Alternatively, after making the three axes of the operating space coordinate system and the three axes of the measuring instrument coordinate system parallel to each other, another jig is placed, and the predetermined jig is specified in each of the operating space coordinate system and the measuring instrument coordinate system. The shift amount can also be obtained from the difference in the coordinates of the positions. The jig used to obtain the shift amount does not necessarily have to be a rectangular parallelepiped shape, and a jig having an appropriate shape capable of defining the predetermined position can be used. For example, when it is difficult to accurately measure the shape of the edge portion when acquiring the entire profile of the rectangular parallelepiped block 52, it is preferable to use the cylindrical block. Further, the jig used for calculating the shift amount is not limited to the block, and the coordinates of the center located on the XY plane and the height from the center are known, and the three-dimensional measurement data is measured by the three-dimensional sensor 4. Can be used as appropriate.

Currently, in the manufacturing industry, there is an urgent need to popularize robots that can replace human power due to the declining population. However, integration of systems using robots and 3D measuring instruments requires advanced knowledge, so it is not always easy for field workers. In particular, in the automobile industry where robots manufactured by various robot manufacturers are used, operability differs depending on the robot manufacturer, so it may be necessary to dispatch specialized engineers who are familiar with the operation. It is difficult to secure and develop human resources. For example, while using the robot, an unexpected collision or the like may occur and the mounting position of the three-dimensional measuring instrument may shift. Since prompt recovery is required in the field, an alignment technique that can be commonly applied to robots manufactured by various robot manufacturers without having advanced knowledge is required, and the present invention can be preferably used. it can.

With the spread of industrial robots and the sophistication of sensing technology such as cameras used to control industrial robots, all tertiary not only the appearance but also the inside of the object are used for the purpose of visual inspection and reverse engineering. There is an increasing need to acquire data of the original shape with high accuracy. In addition, the size of the object is also increasing, and there is a need to scan the entire train or automobile. However, in a system in which the conventional technology is advanced as it is, processes such as arithmetic processing become complicated, and it is becoming difficult to deal with it unless an engineer is familiar with not only robots but also technologies such as programming related to three-dimensional measurement.
In the second and third embodiments, when integrating the three-dimensional measurement data of the object by the optical cutting method using a measuring instrument such as a three-dimensional sensor attached to the robot, a complicated calculation as in the conventional case is performed. The operator can integrate the three-dimensional measurement data acquired in different coordinate systems in a simple process without the need for a program.

1, 100, 200, 300 ... Robot system 2 ... Robot 20 ... Operating point 21 ... Arm unit 22a-22c ... Linear mechanism 23a-23c ... Rotation mechanism 3 ... Controller 31 ... Operating space coordinate system setting unit 4 ... Three-dimensional sensor 41 ... Slit light irradiation unit 42 ... Area sensor 43 ... Control / processing unit 431 ... Storage unit 432 ... Projection line acquisition unit 433 ... Measuring instrument attitude calculation unit 44 ... Communication interface 45 ... Input unit 46 ... Display unit 5 ... Jig 51 ... Plate-shaped member 52 ... Blocks 6, 7 ... Control / processing device 61 ... Storage unit 62 ... Three-dimensional measurement data processing program 621 ... Displacement acquisition unit 622 ... Conversion matrix creation unit 623 ... Three-dimensional measurement data acquisition unit 624 ... Third-order Original measurement data integration unit 45 ... Input unit 65 ... Input unit 66 ... Display unit

Claims (14)

The robot coordinate system, which is the coordinate system of the robot for moving the operating point three-dimensionally, and the coordinate system of the three-dimensional measuring instrument, which can execute the optical cutting method and whose position and orientation with respect to the operating point are invariant. It is a method of aligning the coordinate system of the measuring instrument.
The first reference point located at the origin in the operating space coordinate system, which is the coordinate system of the operating space of the operating point, and the second reference point and the third reference point located on two straight lines orthogonal to the first reference point, respectively. By moving the motion point to and teaching the position of each reference point, the relationship between the motion space coordinate system and the robot coordinate system is determined.
On the surface of the plate-shaped member arranged parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A rectangular parallelepiped reference object fixed to the above is irradiated with a sheet-shaped slit light from the three-dimensional measuring instrument to acquire a projection line to the reference object by the slit light.
Based on the profile of the projection line, the posture of the three-dimensional measuring instrument with respect to the reference object is obtained.
A coordinate system alignment method for a robot, which comprises a step of moving the three-dimensional measuring instrument so that the posture of the three-dimensional measuring instrument falls within a predetermined reference posture range. After moving the three-dimensional measuring instrument so that the posture of the three-dimensional measuring instrument falls within a predetermined reference posture range, further
The difference is obtained by comparing the coordinates of the predetermined position of the reference object in the operating space coordinate system with the coordinates in the measuring instrument coordinate system.
The coordinate system alignment method for a robot according to claim 1, further comprising a step of shifting the measuring instrument coordinate system by the difference. The first or second aspect of the operating space coordinate system is characterized in that the first reference point is the origin, and the second reference point and the third reference point are points on the axis of the coordinate system. The coordinate system alignment method for the robot described. The coordinate system for a robot according to any one of claims 1 to 3, wherein the reference object is arranged so that the three sides of the reference object are parallel to the three axes of the operating space coordinate system. Alignment method. The invention according to any one of claims 1 to 4, wherein the slit light has a width in one axial direction of the measuring instrument coordinate system and is emitted in another uniaxial direction of the measuring instrument coordinate system. Coordinate system alignment method for robots. As the operating space coordinate system, a reference operating space coordinate system and a reference operating space coordinate system are set.
The operating point is moved between the origin of the reference operating space coordinate system and the origin of the reference operating space coordinate system to obtain translational displacement and rotational displacement.
Based on the translational displacement and the rotational displacement, a transformation matrix for converting the reference operating space coordinate system into the reference operating space coordinate system is obtained.
In each of the reference motion space coordinate system and the reference motion space coordinate system, the three-dimensional measuring instrument is moved so that the posture of the three-dimensional measuring instrument falls within the predetermined reference posture range, and the object is three-dimensional. Get measurement data,
The object acquired in the reference space coordinate system by converting the three-dimensional measurement data of the object acquired in the reference operation space coordinate system into the three-dimensional measurement data of the reference operation space coordinate system using the conversion matrix. The coordinate system alignment method for a robot according to any one of claims 1 to 5, wherein the coordinate system alignment method is integrated with three-dimensional measurement data of an object. For each of the plurality of robots, a plurality of operating space coordinate systems are set, which are the plurality of the operating space coordinate systems, one of which is common to the operating space coordinate system set for at least one other robot. ,
One of all the motion space coordinate systems set in the plurality of robots is the reference motion space coordinate system, and the other is the reference motion space coordinate system.
Among the coordinate systems set in the plurality of robots, a transformation matrix for converting the reference motion space coordinate system to the reference motion space coordinate system is created.
Three-dimensional measurement data of the object is acquired in each of the plurality of operating space coordinate systems set for each of the plurality of robots.
The robot according to claim 6, wherein the three-dimensional measurement data of the object acquired in the reference motion space coordinate system is converted into three-dimensional measurement data of the reference motion space coordinate system and integrated. Coordinate system alignment method. The coordinate system alignment system for a robot according to claim 7, wherein the reference operating space coordinate system is set for all of the plurality of robots. The robot coordinate system, which is the coordinate system of the robot for moving the operating point three-dimensionally, and the coordinate system of the three-dimensional measuring instrument, which can execute the optical cutting method and whose position and orientation with respect to the operating point are invariant. A system that aligns the coordinate system of measuring instruments
The first reference point located at the origin in the operating space coordinate system, which is the coordinate system of the operating space of the operating point, the second reference point and the third reference point located on two straight lines orthogonal to the first reference point, respectively. An operating space coordinate system setting unit that determines the relationship between the operating space coordinate system and the robot coordinate system by moving the operating point to a point and teaching the position of each reference point.
On the surface of the plate-shaped member arranged parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A projection line acquisition unit that irradiates a rectangular parallelepiped reference object fixed to the reference object with a sheet-shaped slit light from the three-dimensional measuring instrument and acquires a projection line to the reference object by the slit light.
A measuring instrument posture calculation unit that obtains the posture of the three-dimensional measuring instrument with respect to the reference object based on the profile of the projection line.
A coordinate system alignment system for a robot, which comprises a measuring instrument moving unit for moving the three-dimensional measuring instrument. The operating space coordinate system setting unit sets the reference operating space coordinate system and the reference operating space coordinate system as the operating space coordinate system.
further,
A displacement acquisition unit that moves the operating point between the origin of the reference operating space coordinate system and the origin of the reference operating space coordinate system to acquire translational displacement and rotational displacement.
A transformation matrix calculation unit that obtains a transformation matrix that converts the reference motion space coordinate system into the reference motion space coordinate system based on the translational displacement and the rotational displacement.
In each of the reference motion space coordinate system and the reference motion space coordinate system, the three-dimensional measuring instrument is moved by the measuring instrument moving unit so that the posture of the three-dimensional measuring instrument falls within the predetermined reference posture range. , The 3D measurement data acquisition unit that acquires the 3D measurement data of the object,
The object acquired in the reference space coordinate system by converting the three-dimensional measurement data of the object acquired in the reference operation space coordinate system into the three-dimensional measurement data of the reference operation space coordinate system using the conversion matrix. The coordinate system alignment system for a robot according to any one of claims 1 to 5, further comprising a three-dimensional measurement data integration unit that integrates the three-dimensional measurement data of an object. further,
Equipped with multiple robots
The operating space coordinate system setting unit is common to a plurality of the operating space coordinate systems set for each of the plurality of robots, one of which is set for at least another robot. A plurality of operating space coordinate systems are set, and one of the operating space coordinate systems set for the plurality of robots is set as the reference operating space coordinate system, and the other is set as the reference operating space coordinate system.
The transformation matrix calculation unit creates a transformation matrix that converts the reference motion space coordinate system into the reference motion space coordinate system among the coordinate systems set in the plurality of robots.
The three-dimensional measurement data integration unit acquires three-dimensional measurement data of the object in each of the plurality of operating space coordinate systems set for each of the plurality of robots.
The three-dimensional measurement data integration unit converts the three-dimensional measurement data of the object acquired in the reference motion space coordinate system into the three-dimensional measurement data of the reference motion space coordinate system and integrates the data. The coordinate system alignment system for a robot according to claim 6. The optical cutting method can be executed with the operating space coordinate system, which is the coordinate system of the operating space of the operating point, which is previously associated with the robot coordinate system, which is the coordinate system of the robot for moving the operating point three-dimensionally. Yes A device used to align the coordinate system of a three-dimensional measuring instrument whose position and orientation with respect to the operating point are invariant.
On the surface of the plate-shaped member arranged parallel to the plane on which two of the three orthogonal axes defining the operating space coordinate system are placed, each side is parallel to each of the three orthogonal axes. A projection line acquisition unit that irradiates a rectangular parallelepiped reference object fixed to the reference object with a sheet-shaped slit light from the three-dimensional measuring instrument and acquires a projection line to the reference object by the slit light.
A measuring instrument posture calculation unit that obtains the posture of the three-dimensional measuring instrument with respect to the reference object based on the profile of the projection line.
A coordinate system alignment device for a robot, which comprises. further,
A coordinate system shift unit is provided which obtains a difference by comparing the coordinates of the predetermined position of the reference object in the operating space coordinate system with the coordinates in the measuring instrument coordinate system and shifts the measuring instrument coordinate system by the difference. 7. The coordinate system alignment device for a robot according to claim 7. further,
The invention according to claim 7 or 8, wherein the display unit for displaying the posture of the three-dimensional measuring instrument with respect to the reference object is provided every time the posture of the three-dimensional measuring instrument is obtained by the measuring instrument posture calculation unit. Coordinate system alignment device for robots.

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